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Abstract:

A magnetic valve includes a main body and a closure element, which is
connected to an end region of the main body and which can be impinged by
a fluid pressure. The main body has at least one first support surface
allocated to the closure element in the end region thereof. A support
element is provided, which is connected to the main body and has at least
one other second support surface serving as a bearing surface or forms
the bearing surface together with the first support surface. The bearing
surface is larger than the first support surface.

Claims:

1. A solenoid valve comprising: a basic body; a closing element adjoining
an end region of the basic body; and a supporting element connected to
the basic body, wherein the closing element is capable of being acted
upon with a fluid pressure, wherein the basic body having includes in its
end region at least one first supporting surface assigned to the closing
element, wherein the supporting element includes at least one further,
second supporting surface configured (i) to serve as a bearing surface or
(ii) together with the first supporting surface forms the bearing
surface, and wherein the bearing surface being is larger than the first
supporting surface.

2. The solenoid valve as claimed in claim 1, wherein the supporting
element is connected to the basic body and/or to the closing element in a
positive, nonpositive and/or materially integral manner.

3. The solenoid valve as claimed in claim 1, wherein the supporting
element lies at least in regions on the supporting surface of the basic
body and/or in a groove formed in the region of the supporting surface.

4. The solenoid valve as claimed in claim 1, wherein the second
supporting surface is of annularl design and/or frames the first
supporting surface.

6. The solenoid valve as claimed in claim 1, wherein the supporting
element engages at least in regions into a central recess of the basic
body or surrounds the basic body at least in regions.

7. The solenoid valve as claimed in claim 1, wherein a housing of the
solenoid valve frames at least in regions the basic body, the supporting
element and/or the closing element.

8. The solenoid valve as claimed in claim 1, characterized by wherein the
closing element is arranged outside the housing.

9. The solenoid valve as claimed in claim 1, wherein at least one fluid
connection is formed in the basic body and/or in the closing element
and/or the closing element forms the fluid connection.

10. A driver assistance device, comprising: at least one solenoid valve,
including (i) a basic body (ii) a closing element adjoining an end region
of the basic body and (iii) a supporting element connected to the basic
body, wherein the closing element is capable of being acted upon with a
fluid pressure, wherein the basic body having includes in the end region
a first supporting surface for supporting the closing element, wherein
the supporting element includes a further, second supporting surface
serving configured (i) to serve as a bearing surface for the closing
element or (ii) together with the first supporting surface forms the
bearing surface, and wherein the bearing surface is larger than the first
supporting surface.

Description:

[0001] The invention relates to a solenoid valve with a basic body and
with a closing element adjoining an end region of the basic body and
capable of being acted upon with a fluid pressure, the basic body having
in its end region at least one first supporting surface assigned to the
closing element. The invention relates, furthermore, to a driver
assistance device.

PRIOR ART

[0002] Solenoid valves of the type initially mentioned are known from the
prior art. They are designed, for example, as currentlessly open or
currentlessly closed 2/2-way solenoid valves. Such a solenoid valve
serves as a technical component for controlling an inlet or outlet of
gases or liquids or for controlling or regulating a flow direction. An
inlet connection, through which the fluid, that is to say either gas or
liquid, enters the solenoid valve, is often arranged in the closing
element which adjoins the basic body or the end region of the latter. A
force caused by the pressure of the fluid therefore acts upon the closing
element. This force is caused, for example, by a pressure difference,
particularly when the solenoid valve is closed, or by surfaces of the
closing element which are of different size and are acted upon with the
fluid. This force has to be absorbed by the basic body.

[0003] For this purpose, the latter has the first supporting surface which
is assigned to the closing element. The supporting surface serves for
supporting the closing element in the axial direction, particularly when
the force urge the closing element toward the basic body. A very high
pressure may be exerted upon the closing element or the basic body as the
function of the force. This pressure is dependent on the area of the
supporting surface. The support, known from the prior art, of the closing
element on the basic body via the supporting surface may sometimes lead
to a reduced fatigue strength of the solenoid valve, so that this
possibly has to be exchanged more frequently.

DISCLOSURE OF THE INVENTION

[0004] By contrast, the solenoid valve having the features mentioned in
claim 1 has the advantage that the fatigue strength of the solenoid valve
is improved. This is achieved, according to the invention, by means of a
supporting element which is connected to the basic body and which has at
least one further, second supporting surface serving as a bearing surface
for the closing element or together with the first supporting surface
forms the bearing surface, the bearing surface being larger than the
first supporting surface. Thus, the pressure which is exerted upon the
closing element by the fluid can be reduced by the amount by which the
area of the bearing surface is larger than the area of the supporting
surface. For this purpose, the supporting element is fastened to the
basic body. Said supporting element has the second supporting surface.
The latter may serve, in a first embodiment, as the sole bearing surface
for the closing element. For example, in this case, the supporting
element itself is supported on the supporting surface of the closing
element and makes available the second supporting surface for supporting
the closing element in the axial direction. In a second embodiment, the
second supporting surface forms together with the first supporting
surface the bearing surface. For this purpose, the second supporting
surface is arranged flush or in alignment with the first supporting
surface, so that together they form a planar surface, to be precise the
bearing surface. This has a larger area than the first supporting
surface.

[0005] In a development of the invention, the supporting element is
connected to the basic body and/or to the closing element in a positive,
nonpositive and/or materially integral manner. Basically, the supporting
element may be connected in any way to the basic body or to the closing
element. The supporting element is usually pressed onto the basic body,
so that there is a nonpositive connection. In this case, the bearing
surface usually serves merely for supporting the closing element. The
fastening of the closing element to the basic body does not have to be
achieved by fastening the closing element to the supporting element.

[0006] In a development of the invention, the supporting element lies at
least in regions on the supporting surface of the basic body and/or in a
groove formed in the region of the supporting surface. In order to fasten
the supporting element itself in the axial direction, there may be
provision for it to be supported at least in regions on the supporting
surface of the basic body. This means that the supporting element lies on
the supporting surface and via the supporting surface introduces into the
basic body a force acting upon the supporting element. Alternatively or
additionally, a groove, by means of which the axial fastening of the
supporting element is implemented, can also be formed in the region of
the (first) supporting surface. The groove is in this case a groove which
is encircling at least in regions, in particular completely, and by means
of which, for example, a latching connection between the supporting
element and basic body is implemented. The groove also at the same time
makes it easier to orient the first supporting surface with respect to
the second supporting surface.

[0007] In a development of the invention, the second supporting surface is
of annular design and/or frames the first supporting surface. Basically,
the second supporting surface may have any shape. Usually, however, the
basic body of the solenoid valve is cylindrical, that is to say has a
cross section which at least in regions is round. For this reason, the
second supporting surface is advantageously annular. In the second
embodiment in which the second supporting surface forms together with the
first supporting surface the bearing surface, there may be provision for
the second supporting surface to frame the first supporting surface at
least partially in the circumferential direction. Advantageously, the
second supporting surface is designed as a ring completely surrounding
the first supporting surface.

[0008] In a development of the invention, the closing element and/or the
supporting element are/is composed of plastic and/or metal. The material
for these elements is selected as a function of the force acting upon the
closing element or the supporting element. In the case of low load, for
example, it may be advantageous to use plastic both for the closing
element and for the supporting element for reasons of cost. Under higher
pressure load, however, the supporting element, in particular, may be
formed from metal.

[0009] In a development of the invention, the supporting element engages
at least in regions into a central recess of the basic body, in
particular is held between the basic body and a sealing body of the
solenoid valve, or surrounds the basic body at least in regions. In order
to fasten the supporting element to the basic body basically two
possibilities are therefore provided. The first possibility provides for
the supporting element to engage into the basic body; in the second
possibility, the basic body is surrounded by the supporting element. In
this case, in particular, clamping fastening of the supporting element to
the basic body is provided. For example, in the first possibility, the
supporting element may be slightly larger than the central recess of the
basic body into which said supporting element engages. Alternatively, if
the supporting element surrounds the basic body, internal dimensions of
the supporting element are slightly smaller than external dimensions of
the basic body, so that a clamping hold is implemented.

[0010] If the supporting element is to engage into the central recess, it
is especially advantageous if it is held by clamping between the basic
body and a sealing body of the solenoid valve. The sealing body is
provided in the solenoid valve, for example, to form a valve seat which
co-operates with a sealing element in order to open or to close the
solenoid valve. There may be provision, then, whereby, first, the
supporting element is introduced into the central recess of the basic
body, and then the sealing body is pressed into the supporting element in
such a way that the latter expands at least slightly and a clamping
connection to the basic body is thus made. Both the supporting element
and the sealing body are thereby held in the solenoid valve or in the
basic body. In such a version, however, it is advantageous if additional
holding means are provided in order to secure the connection between the
supporting element, sealing body and basic body permanently.

[0011] In a development of the invention, a housing of the solenoid valve
frames at least in regions the basic body, the supporting element and/or
the closing element. The housing is intended, in particular, to fasten
the solenoid valve to an external device or to connect it to the latter.
For this purpose, said housing frames at least the basic body at least in
regions. Additionally or alternatively, there may also be provision for
the supporting element or the closing element to be arranged at least in
regions in the housing. The leaktightness of the solenoid valve and the
fastening of the basic body, supporting element and closing element to
one another are thereby improved.

[0012] In a development of the invention, the closing element is arranged
outside the housing. In this case, therefore, the housing frames, for
example, only the basic body and/or the supporting element. By contrast,
the closing element is provided outside the housing. In this case, there
may be provision for the closing element to be connected either to the
basic body, the supporting element and/or the housing so as to implement
the fastening of the closing element to the solenoid valve.

[0013] In a development of the invention, at least one fluid connection is
formed in the basic body and/or in the closing element and/or the closing
element forms the fluid connection. The fluid connection may, for
example, be the inlet connection or else an outlet connection of the
solenoid valve. For example, the inlet connection may be formed in the
closing element and the outlet connection may be formed in the basic
body. In this case, there may be provision for the closing element to
form the fluid connection, that is to say to directly have means for
making a fluid connection between an external device and the solenoid
valve.

[0014] The invention relates, furthermore, to a driver assistance device,
in particular ABS, TCS or ESP device, with at least one solenoid valve,
particularly according to the above versions, which has a basic body and
a closing element adjoining an end region of the basic body and capable
of being acted upon with a fluid pressure, the basic body having in the
end region a first supporting surface for supporting the closing element.
In this case, a supporting element is provided which is connected to the
basic body and which has a further, second supporting surface serving as
a bearing surface for the closing element or together with the first
supporting surface forms the bearing surface, the bearing surface being
larger than the first supporting surface. The solenoid valves described
above are suitable especially for use in such a driver assistance device,
since, in such as this, high pressures, for example brake pressures, are
often to be set by means of the solenoid valve. For example, the solenoid
valves are in this case assigned to braking devices which belong to the
driver assistance device or are at least activated by the latter.

[0015] The invention is explained in more detail below by means of the
exemplary embodiments illustrated in the drawing, without any restriction
occurring. In the drawing:

[0016]FIG. 1 shows a cross section of a solenoid valve not according to
the invention which has a basic body and a closing element,

[0017]FIG. 2 shows the basic body of the solenoid valve in an embodiment
according to the invention in a side view, a supporting element being
mounted on the basic body, and

[0018]FIG. 3 shows the basic body with the supporting element in a top
view, a bearing surface formed by supporting surfaces of the supporting
element and of the basic body being visible.

[0019]FIG. 1 shows a sectional side view of a solenoid valve 1 which is
known from the prior art in the embodiment illustrated here. The solenoid
valve is composed of a basic body 2 which is designated also as a valve
insert. The basic body 2 is enclosed at least in regions by a housing 3.
A magnet armature 4 and an actuation element 5 adjoining the latter are
mounted in the basic body 2 axially movably with respect to a
longitudinal axis 6 of the solenoid valve 1. The actuation element 5 has
on its side facing away from the magnet armature 4 a sealing element 7
which co-operates with a valve seat 9 formed in a sealing body 8 in order
to make or brake a flow connection from a first fluid connection 10,
which is designed as an inlet connection, to a second fluid connection
11, which constitutes an outlet connection.

[0020] In an end region 12 of the basic body 2, a closing element 13
adjoins the latter. In this case, the first fluid connection 10 is
provided in this closing element 13 or is formed by the closing element
13. The closing element 13 is supported in the axial direction on a first
supporting surface 14 which is formed by the basic body 2. This first
supporting surface 14 in this case forms a bearing surface 15 for the
closing element 13. Particularly when the solenoid valve 1 is closed,
that is to say the sealing element 7 is seated in the valve seat 9 in
such a way that there is no fluid communication between the fluid
connections 10 and 11, a higher pressure is present at the first fluid
connection 10 than at the second fluid connection 11 or in a fluid
chamber 16. The fluid chamber 16 is in this case in permanent flow
communication with the second fluid connection 11 and is formed or
surrounded at least in regions by the basic body 2.

[0021] When the higher pressure is present at the first fluid connection
10, the closing element 13 is urged in the direction of the basic body 2
by this pressure. The pressure difference between the fluid connections
10 and 11 thus gives rise to a force upon the closing element 13 in the
direction of the basic body 2. This force is absorbed by the bearing
surface 15, both the basic body and the closing element 13 being exposed
to a corresponding pressure or tension. In the embodiment of the solenoid
valve 1 illustrated here, the area of the bearing surface 15 is
comparatively small, so that a comparatively high pressure is applied to
the basic body 2 and the closing element 13. Since the closing element 13
is usually composed of plastic, this may give rise to surface stress or
surface load which is detrimental to the fatigue strength of the solenoid
valve 1, since it may sometimes cause damage to the closing element 13.

[0022] For this reason, the basic body 2 in which the fluid connections 11
are present is assigned a supporting element 17 which is connected to the
basic body 2. This is illustrated in FIG. 2. The supporting element 17
forms a further, second supporting surface 18 which is arranged flush or
in alignment with the first supporting surface 14. The supporting
surfaces 14 and 18 can thus together form a bearing surface 15 which has
a larger area than the first supporting surface 14. In such an embodiment
of the solenoid valve 1, the pressure which acts upon the closing element
13 lying on the bearing surface 15 is markedly reduced. The operational
durability of the solenoid valve is thereby reduced by the reduction in
the surface load of the closing element 13. The supporting element 17 may
therefore also be designated as a reinforcing part.

[0023] As can be seen in FIG. 3, the supporting element 17 is of annularl
design and completely surrounds the basic body 2 in the circumferential
direction. In this case, the supporting element 17 is, for example,
pressed onto the basic body 2, so as to make between an inner face 19 of
the supporting element 17 and an outer face 20 of the basic body 2 a
clamping connection via which the supporting element 17 is held securely
on the basic body 2.

[0024] In this case, as already stated above, the first supporting surface
14 of the basic body 2 and the second supporting surface 18 of the
supporting element 17 are arranged flush or in alignment with one another
so as to form the bearing surface 15 for the closing element 13, the
bearing surface 15 therefore being of planar form. It becomes clear that,
by the supporting element 17 being provided, the bearing surface 15 is
markedly enlarged, as compared with the solenoid valves 1 known from the
prior art. Thus, the pressure acting upon the closing element 13 or the
tensions in the closing element 13 which are caused by said pressure can
be reduced, since the force upon the closing element 13 caused by the
pressure of the fluid is applied to a larger area, to be precise to the
joint area of the supporting surfaces 14 and 18. Solenoid valves 1 of
this type can be used especially advantageously in conjunction with
driver assistance devices, for example ABS, TCS or ESP devices.